Top or Side?
On an E-35 Mk3, the "toe rail" being asked about is likely just the cosmetic cover over the hull-to-deck joint that was already glassed over on the inside with roving. This is the standard scheme on the 80's Ericson series. Strong construction and you end up with a "one piece" hull and deck structure.
There is a raised toe rail that is part of the mold, but I do not believe that is what is being discussed by the thread starter.
(The Olsons were constructed differently, with an inward flange on the hull mold and the deck placed on top and thru-bolted thru an aluminum slotted toe rail. Generally equal in strength, but rather different in design/engineering.)
The boat in the original post would have an extruded aluminum cover piece with a vinyl fill piece. Before the vinyl is pressed into place, that aluminum section is screwed into the joint with a whole lotta small ss screws, IIRC. The outside groove of that joint was faired first with some poly putty, and then the cover was applied.
Over the decades, that long continuous alum. piece can be damaged by contact with docks, boats, UFO's, and whatever.... and sometimes it can corrode over the decades from moisture trapped in the channel in the center. I am not at all sure who/where you can source a new section, and if you do, shipping would be a bear (not knowing if it could be rolled up and how many feet accross that roll might have to be!).
Strictly in the "FWIW" department, I have seen one similar Ericson 34 (80's model) with the whole joint finished out smooth on the outside and painted with LPU to match the hull. IIRC they did a new Ericson standard wide cove stripe that covered the area, and mostly just painted that one part. I recall that I had to study the boat for a minute to be sure it was an Ericson.... but then I focused on the trapazoidal windows and figured out what I was looking at!
There are all-vinyl change-overs that you could replace both sides with, but IMHO they would look a bit clunkier than the factory original. Hopefully other owners of E boats from the 80's will have some solutions.
Regards,
Loren